With the advent of the of in-line skating in the early 1980's in-line skating has increased in popularity to a point that it is successfully competing and coexisting with traditional roller skating. The popularity of in-line skating has increased since its inception to a point that nearly a worldwide market now purchases in-line skates. With the increased popularity, skaters have become quite sophisticated and demand state of the art equipment. To meet the consumer's demands for lighter, faster skates, in-line skate manufacturers are continually striving to develop new skates.
Wheels of in-line skates are the subject of constant research and development. Early in-line skate wheels were manufactured out of high friction material which created prohibitively slow wheels. The industry quickly started producing the wheels from materials which had a lower coefficient of friction and thereby created faster wheels.
Although the early in-line skate wheels were slower than currently sold wheels, in-line skates were always faster than traditional roller skates. Without intending to be bound by theory it is believed that the speed of the in-line skates is in part attributed to wheel shape and to wheel mounting. The wheels of in-line skates have traditionally been hemispherical in shape. When coasting on traditional roller skates and on in-line skates, the wheels are without camber. In-line skates have a smaller surface area contacting the pavement as compared to traditional roller skates during coasting because the wheels of traditional roller skates are much wider and flatter than the wheels of in-line skates. Since in-line skates have a much smaller area contacting the pavement, the amount of friction between the wheel surface and the pavement is thereby reduced as compared to traditional roller skates.
In-line skates are distinct from traditional roller skates in manners other than mere wheel shape. The wheel attachment is very different on the two skate types. Wheels of traditional skates are pivotally mounted by "trucks" to the skate shoe. Pivotal mounting allows the wheel axes to remain substantially parallel to the ground at substantially all times. As a skater accelerates by laterally pushing the skate against the ground away from the skater's body, the pivoting wheel axes allow the wheel to remain substantially upright. Thus, in traditional roller skates the portion of the wheel which contacts the pavement remains substantially constant.
Compare this to in-line skates which have wheels rigidly mounted to the skate shoe. As an in-line skater pushes his skate laterally against the ground to accelerate, the wheel axes become inclined relative to the ground causing the wheels to tilt or camber relative to the ground or pavement. Therefore, the wheel portion which contacts the pavement is not constant. The wheel shapes which provide optimal performance on in-line skates as compared to traditional roller skates are very different due to the above-described differences with wheel mounting.
As previously mentioned, the surface of the in-line skate wheel has traditionally been a hemispherical shape. This shape has functioned well to date, however, a wheel shape which is functional on in-line skates and also increases the speed of the skater without increasing the effort would provide a desirable improvement over the existing art.